<span>The correct answer is option B. i.e.invention of the microscope. Galileo Galilei invented the microscope and showed its use. Sir Issac Newton invented some part of the calculus, Also invented Newton's Laws of motion and the universal gravitation theory.</span>
Answer:
the length of the simple pendulum is 0.25 m.
Explanation:
Given;
mass of the air-track glider, m = 0.25 kg
spring constant, k = 9.75 N/m
let the length of the simple pendulum = L
let the frequency of the air-track glider which is equal to frequency of simple pendulum = F
The oscillation frequency of air-track glider is calculated as;

The frequency of the simple pendulum is given as;

Thus, the length of the simple pendulum is 0.25 m.
Answer:
525 Bq
Explanation:
The decay rate is directly proportional to the amount of radioisotope, so we can use the half-life equation:
A = A₀ (½)^(t / T)
A is the final amount
A₀ is the initial amount,
t is the time,
T is the half life
A = (8400 Bq) (½)^(18.0 min / 4.50 min)
A = (8400 Bq) (½)^4
A = (8400 Bq) (1/16)
A = 525 Bq